Wastewater treatment plant is not upgraded if the service life is generally 20 to 30 years, if the period for major repairs or upgrades should be appropriate to refresh the new part of the service life. Wastewater treatment plants are generally no more than 30 years, the structural part of the building structures at least 50 years of service life.
Less than 2 years are temporary buildings can not be considered sewage treatment plant buildings.